1. Field of the Invention
The present invention relates to a multiple single nucleotide polymorphism (multi-SNP) marker for diagnosing cardiovascular disease, a method of diagnosing cardiovascular disease using the same, and a set of polynucleotides, a microarray and kit for performing the method.
2. Description of the Related Art
The genomes of all organisms undergo spontaneous mutation in the course of their continuing evolution, generating variant forms of progenitor nucleic acid sequences. (Gusella, Ann. Rev. Biochem. 55, 831-854, 1986). The variant forms of progenitor nucleic acid sequences may confer an evolutionary advantage or disadvantage, or may be neutral relative to a progenitor form. In some instances, a variant form confers a lethal disadvantage and is not transmitted to subsequent generations of the organism. In other instances, a variant form confers an evolutionary advantage to the species and is eventually incorporated into the DNA of most members of the species and effectively becomes the progenitor form. In many instances, both progenitor and variant forms survive and coexist in a species population. The coexistence of multiple forms of a sequence gives rise to polymorphisms.
Several types of polymorphisms are known, including restriction fragment length polymorphism (RFLP), short tandem repeats (STR) and single nucleotide polymorphism (SNP). Among them, a “SNP” is variation of a single nucleotide in a nucleic acid sequence among individuals of the same species. When a SNP occurs in a protein coding sequence of a gene, one of the polymorphic forms may give rise to a non-synonymous codon change, causing expression of a defective or a variant protein. When a SNP occurs in a non-coding sequence of a gene, one of the polymorphic forms may also cause the expression of a defective or variant protein, for example, as a result of defective splicing of mRNA. Other SNPs have no phenotypic effect.
It is estimated that human SNPs occur at a frequency of 1 in every 1,000 bp. When such a SNP induces a phenotypic expression such as the presence or absence of a disease, polynucleotides containing an allele of the SNP can be used as a primer or a probe for diagnosis of the disease. Monoclonal antibodies specifically binding with an amino acid sequence resulting from one of the alleles of the SNP can also be used in the diagnosis of the disease. Currently, research into the nucleotide sequences and functions of SNPs is being performed by many research institutes. The nucleotide sequences and results of other experiments on identified human SNPs have been put in databases to be easily accessible.
Even though findings available to date show that specific SNPs exist in human genomes or cDNAs, the phenotypic effects of SNPs have not been revealed. Functions of most SNPs have not yet been discovered.
Cardiovascular disease is a major cause of death in industrialized countries around the world, and has been a major cause of death in the Republic of Korea since the 1970s. According to the Korea National Statistical Office, in 2003, 22,000 out of 246,000 deaths (9087 per 100,000, or 9.1%) were the result of cardiac disorder and hyperpiesia, which are the third leading cause of death following cancer and cerebrovascular disease.
Cardiovascular disease includes myocardial infarction, angina pectoris, atherosclerosis, hyperpiesia, cardiac failure, aneurysm, arteriosclerosis, embolism, stroke and thrombosis.
Coronary artery disease, which ranks high among cardiovascular diseases, is usually caused by arteriosclerosis, the blocking or narrowing of coronary artery supplying blood to the heart. Blocking of the coronary artery indicates myocardial infarction and narrowing of the coronary artery indicates angina pectoris. Risk factors for coronary artery disease are known to be hyperlipidemia (hypercholesterolemia), hyperpiesia, smoking, diabetes, genetic inheritance, obesity, lack of exercise, stress and menopause. A person having more risk factors for a disease has a higher risk of incidence of the disease. Cardiovascular disease, like other diseases, is also influenced by genetic factors.
The most serious problem in the diagnosis and prognosis of various cardiovascular diseases and associated diseases is that the diagnosis can be performed using a physical technique only when the diseases are at an advanced stage. Currently, X-ray and ultrasonography of the interior of the heart and coronary artery can be used for cardiovascular disease diagnosis, but this diagnosis is only possible at an advanced stage of the disease. However, the developments of recent molecular biological techniques and the primary completion of the human genome project enable the detection of genes or genetic variations directly or indirectly related to a cardiovascular disease. Therefore, early diagnosis of a cardiovascular disease using a genetic factor, instead of using a conventional diagnostic method depending on phenotype or physical characteristics of the disease, has become available.